Viruses are tiny but powerful intrusions that can be found in the environment, including in human bodies, and they can play a variety of roles in ecosystems. Viruses also come in a wide variety of sizes, according to scientists. These are of course, some of whom were previously thought to be rare cases.
Among these large viruses are bacterial viruses called jumbo bacteriophages. Despite being discovered decades ago, jumbo phages have, quite surprisingly, escaped further research because scientists were looking on too large of a scale.
A Ph.D. candidate, and Frank Aylward, an adjunct professor of biology at the Virginia Tech College of Science and an affiliate professor at theCenter for Emerging, Zoonotic, Arthropod-borne pathogens at the University of Michigan, are attempting to answer a few big questions about these jumbo viruses. In a recent study, Weinheimer investigated and investigated the genomes of marine jumbo phages, which led to a number of conclusions about their evolution and ecology.
According to Weinheimer, we are beginning to understand the diversity and scope of jumbo phages in the environment, and the first author on the paper. We''re yet to understand how these jumbo phages are occurring. This study shows that they are everywhere in the ocean, and they don''t necessarily all infect the same type of bacteria.
Their findings were published in the ISME Journal: Multidisciplinary Journal of Microbial Ecology.
Bacteria are the driving force behind the ocean''s nutrient cycles. Despite their position at the bottom of the food chain, bacteria perform vital functions such as photosynthesis and nitrogen fixation, which contribute greatly to the health of marine ecosystems.
When jumbo bacteriophages invade and kill bacteria, they first encrypt control of the bacterias'' metabolism, transforming the bacteria''s primary functions such as photosynthesis and transcription into the replication of more viruses. The bacteria cell bursts to release new viruses, which also releases the cells nutrients and organic material into the ocean. These infections transform nutrient cycles in the ocean.
Researchers are determined to understand how phages alter marine microbial communities and nutrient pathways that bacteria affect. However, they must work beyond a basic microscopic level to research viruses.
Viruses are often difficult to grow in a lab, so researchers often go out and collect metagenomes'' DNA samples. Each metagenome sample is composed of essential amino acids, which means researchers must isolate and together the viruses'' genomes.
From there, the process takes place like constructing an incomplete puzzle.
When we sequence DNA in the environment, we first need to break the DNA into itty bitty pieces, according to Weinheimer. After they are sequenced, we put the pieces back together into long term stretches of DNA that we believe belong to the same genome.
Due to their profound evolution and dynamics, researchers must adopt innovative techniques to detect jumbo phages and reconstruct their genomes as accurately and effectively as possible.
After a lengthy trial and error, Weinheimer and Aylward developed a method that would help other researchers better identify and group jumbo bacteriophages in metagenomes.
Weinheimer and Aylward were able to successfully recover 85 high-quality jumbo phage genomes in the ocean. They then divided these jumbo phages based on gene content with other known jumbo phages, and they were able to conclude that certain groups of jumbo phages are more prevalent in surface waters than deep waters.
According to Weinheimer, traditional methods only focus on a fragment of jumbo phage genomes. However, with our approach, we''re approaching full genomes, and therefore we''re able to improve our understanding of these phages'' diversity and biology.
In their research, Weinheimer and Aylward say that bacteriophages have different paths of developing such big genomes. While some phages may acquire photoynthetic genes to help in infection efficiency, others may pick up genes that are more important in combating their host''s defenses.
This study bolsters the assumption that a defense system weapons race is partly the cause behind the enormous amount and diversity of bacteriophage genomes.
But there should be more work to understand how complex the virus world evolves or emerges, and how they evolve with their hosts. Now that Weinheimer and Aylward know where these jumbo phages are more prevalent, they may collect samples to develop them in the lab.
According to Weinheimer, by targeting and isolating jumbo phages or by cultivating them in the lab, we may better understand their biology. A lot of jumbo phages have genes with unknown functions, and we are curious to see what we will discover.
To begin to see what roles might play in these ecosystems, their methods may be applied to metagenome samples from other environments such as soils and lakes.